Chromatography, Chemistry

Assignment Help:

The process of chromatography involves passing a mixture dissolved in the "mobile phase" through a stationary phase, which separates the analyte which is to be measured from the other molecules in the mixture based on differential partitioning in between the mobile and stationary phases. Subtle differences in a compound's partition coefficient resulting in differential retention on stationary phase and therefore changing the separation. Method of chromatography is stated below.

Paper chromatography is a technique which involves placing a small dot or line of sample solution onto the strip of chromatography paper. The paper of it is made of cellulose, a polar substance, and compounds within the mixture travel farther if they are non-polar. More polar substances bond with cellulose paper more quickly, and thus do not travel as far. The paper is placed in a jar having a shallow layer of solvent and sealed. As the solvent rises through the paper, it meets sample mixture which begins to travel up the paper with the solvent. 

Thin layer chromatography (TLC) is an extensively employed laboratory technique and is similar to paper chromatography. But, instead of using the stationary phase of paper, it involves a stationary phase of the thin layer of adsorbent such as alumina, silica gel, or cellulose on a flat, inert substrate. Compared to paper, this has the advantage of faster runs, better separations, and the choice among different adsorbents. For even better resolution and to allow for the quantification, high-performance TLC can be used.

Column chromatography is the separation technique in which the stationary bed is within a tube. The particles of the solid stationary phase or the support coated with a liquid stationary phase may fill the whole inside volume of the tube (packed column) or be concentrated on or along the inside tube wall leaving an open, unrestricted path for the mobile phase in the middle part of the tube (open tubular column). Differences in rates of movement through the medium are calculated to different retention times of the sample. 


Related Discussions:- Chromatography

Urea, What is the nature of urea? Is it acidic basic or neautral how can wr...

What is the nature of urea? Is it acidic basic or neautral how can wr verify it?

Lewis, Alf3 dot structure

Alf3 dot structure

Rehydration tests for the dried sample, Q. Rehydration tests for the dried ...

Q. Rehydration tests for the dried sample? • gain knowledge about the sensory changes that take place during the dehydration of the samples, and • learn about the effectiv

What are co-ordination compounds and its applications?, The co-ordination c...

The co-ordination compounds are of great importance. These compounds constitute the minerals, plants and are also present in animals. These play important functions. For example, c

Treshold frequency, How is threshold frequency related of the incident radi...

How is threshold frequency related of the incident radiation

The valence electron in the carbon atom are, The valence electron in the ca...

The valence electron in the carbon atom are: (1) 0        (2) 2          (3) 4       (4) 6 Ans: 4

Occurrence of group 13 element, Q. Occurrence of group 13 element? Both...

Q. Occurrence of group 13 element? Both boron and aluminium have a high affinity for oxygen, so neither of them is found native. Boron occurs principally in the earth's crust a

Heterocyclic compounds., why isoquinoline is weak base as compare to quinol...

why isoquinoline is weak base as compare to quinoline?#

Study p, P-BLOCK GROUP ELEMENTS:                    The p block elements a...

P-BLOCK GROUP ELEMENTS:                    The p block elements are belong to group 13 to 18.the outermost electronic configuration is ns2 np1 to ns2 np6.these are called represen

What is chlorofluorocarbon, Q. What is chlorofluorocarbon? A chemical i...

Q. What is chlorofluorocarbon? A chemical is some substance that has a definite composition. Ozone is a chemical which is made up of three particles of oxygen. Ozone forms a th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd